reason. The claim that there exists a being outside these two categories contradicts the necessary, innate judgment of reason and is among the gravest forms of sophistry. Such a claim is not to be accepted from anyone. If it is given a hearing, comparable sophistries must also be given a hearing.

The second point is that a distinction must be made between categories possible in external reality and mental suppositions, which need not correspond to external realities. The mind can posit impossible things despite their inability to exist externally. It can suppose what exists to be nonexistent, and what does not exist to be existent, although external reality is otherwise. The scope of mental suppositions is therefore broader than that of categories possible in external reality.

This is because the mind frames its suppositions according to whatever categories it postulates. It can thus say that a thing is either existent, nonexistent, or neither existent nor nonexistent; that a thing is either unknown, known, or neither known nor unknown; and that it is either necessary, impossible, possible, or neither necessary nor impossible nor possible. It can also say that an existent being is either beginningless, originated, or neither beginningless